Iester Michele, Mete Maurizio, Figus Michele, Frezzotti Paolo
Anatomical-Clinical Laboratory for Functional Diagnosis and Treatment of Glaucoma and Neuroophthalmology, Clinica Oculistica, Department of Neurological Sciences, Ophthalmology, Genetic, University of Genoa, Genoa, Italy.
J Cataract Refract Surg. 2009 Sep;35(9):1623-8. doi: 10.1016/j.jcrs.2009.05.015.
Intraocular pressure (IOP) results from a dynamic balance between aqueous humor formation and outflow. The simplest technique to measure IOP is indentation tonometry. Another technique is applanation. These methods are related to the elasticity of the eye, which mainly depends on its thickness and hysteresis. For several decades, Goldmann applanation tonometry has been the most accepted method of measuring IOP; the Goldmann tonometer is still used in all important trials. The relationship between IOP values and central corneal thickness (CCT) is well known; Goldmann stated that this relationship only holds for an average corneal thickness of 520 microm measured by optical pachymetry. The Ocular Hypertension Treatment Study (OHTS) showed that CCT is an important risk factor for a change from ocular hypertension to primary open-angle glaucoma. In a multivariate model that included IOP, CCT was the most powerful component of the predictive model. In the Early Manifest Glaucoma Trial (EMGT) with an 11-year follow-up, CCT was a significant predictive factor for glaucoma progression in patients with higher baseline IOP but not in those with lower baseline IOP. Clinical trials such as the OHTS and EMGT cannot prove that CCT is linked to a risk for glaucoma on a biological level. Thus, in eyes with glaucoma, IOP must be treated because it has a significant influence on progression of glaucoma, regardless of the baseline IOP and CCT.
眼压（IOP）源于房水生成与流出之间的动态平衡。测量眼压最简单的技术是压陷式眼压测量法。另一种技术是压平式眼压测量法。这些方法与眼球的弹性有关，而眼球弹性主要取决于其厚度和滞后性。几十年来，Goldmann压平式眼压测量法一直是最被认可的眼压测量方法；Goldmann眼压计仍用于所有重要试验中。眼压值与中央角膜厚度（CCT）之间的关系是众所周知的；Goldmann指出，这种关系仅适用于通过光学角膜厚度测量法测得的平均角膜厚度为520微米的情况。高眼压治疗研究（OHTS）表明，CCT是从高眼压转变为原发性开角型青光眼的一个重要危险因素。在一个包括眼压的多变量模型中，CCT是预测模型中最有力的组成部分。在进行了11年随访的早期显性青光眼试验（EMGT）中，CCT是基线眼压较高的患者青光眼进展的一个重要预测因素，但在基线眼压较低的患者中并非如此。诸如OHTS和EMGT等临床试验无法证明CCT在生物学层面与青光眼风险有关。因此，在患有青光眼的眼中，必须治疗眼压，因为它对青光眼的进展有重大影响，无论基线眼压和CCT如何。
